Methods for inhibiting bone loss

ABSTRACT

The current invention provides methods and pharmaceutical formulations that are useful for inhibiting the loss of bone. These methods and formulations can be used without the associated adverse effects of estrogen therapy, and thus serve as an effective and acceptable treatment for osteoporosis.

BACKGROUND OF THE INVENTION

[0001] This invention relates to the discovery that a group of2-phenyl-3-aroylbenzothiophenes is useful in the prevention of boneloss.

[0002] The mechanism of bone loss is not well understood, but inpractical effect, the disorder arises from an imbalance in the formationof new healthy bone and the resorption of old bone, skewed toward a netloss of bone tissue. This bone loss includes a decrease in both mineralcontent and protein matrix components of the bone, and leads to anincreased fracture rate of, predominantly, femoral bones and bones inthe forearm and vertebrae. These fractures, in turn, lead to an increasein general morbidity, a marked loss of stature and mobility, and, inmany cases, an increase in mortality resulting from complications.

[0003] Bone loss occurs in a wide range of subjects, includingpost-menopausal women, patients who have undergone hysterectomy,patients who are undergoing or have undergone long-term administrationof corticosteroids, patients suffering from Cushing's syndrome, andpatients having gonadal dysgensis.

[0004] Unchecked, bone loss can lead to osteoporosis, a majordebilitating disease whose prominent feature is the loss of bone mass(decreased density and enlargement of bone spaces) without a reductionin bone volume, producing porosity and fragility.

[0005] One of the most common types of osteoporosis is found inpost-menopausal women affecting an estimated 20 to 25 million women inthe United States alone. A significant feature of post-menopausalosteoporosis is the large and rapid loss of bone mass due to thecessation of estrogen production by the ovaries. Indeed, data clearlysupport the ability of estrogens to limit the progression ofosteoporotic bone loss, and estrogen replacement is a recognizedtreatment for post-menopausal osteoporosis in the United States and manyother countries. However, although estrogens have beneficial effects onbone, given even at very low levels, long-term estrogen therapy has beenimplicated in a variety of disorders, including an increase in the riskof uterine and breast cancer, causing many women to avoid thistreatment. Recently suggested therapeutic regimens, which seek to lessenthe cancer risk, such as administering combinations of progestogen andestrogen, cause the patient to experience regular withdrawal bleeding,which is unacceptable to most older women. Concerns over the significantundesirable effects associated with estrogen therapy, and the limitedability of estrogens to reverse existing bone loss, support the need todevelop alternative therapy for bone loss that generates the desirableeffects on bone but does not cause undesirable effects.

[0006] Attempts to fill this need by the use of compounds commonly knownas antiestrogens, which interact with the estrogen receptor, have hadlimited success, perhaps due to the fact that these compounds generallydisplay a mixed agonist/antagonist effect. That is, although thesecompounds can antagonize estrogen interaction with the receptor, thecompounds themselves may cause estrogenic responses in those tissueshaving estrogen receptors. Therefore, some antiestrogens are subject tothe same adverse effects associated with estrogen therapy.

[0007] The current invention provides methods for inhibiting the loss ofbone without the associated adverse effects of estrogen therapy, andthus serves as an effective and acceptable treatment for osteoporosis.

[0008] The 2-phenyl-3-aroylbenzothiophene compounds that are the activecomponent in the formulations and methods of this invention were firstdeveloped by C. David Jones and Tulio Suarez as anti-fertility agents(see U.S. Pat. No. 4,133,814, issued Jan. 9, 1979). Certain compounds inthe group were found to be useful in suppressing the growth of mammarytumors.

[0009] Jones later found a group of related compounds to be useful forantiestrogen and antiandrogen therapy, especially in the treatment ofmammary and prostatic tumors (see U.S. Pat. No. 4,418,068, issued Nov.29, 1983). One of these compounds, the compound of formula I wherein Xis a bond, R and R¹ are hydroxyl, and R² is a piperidino ring, wasclinically tested for a brief time for the treatment of breast cancer.That compound is called raloxifene, formerly keoxifene.

SUMMARY OF THE INVENTION

[0010] This invention provides new methods for the treatment of boneloss comprising administering to a human in need of treatment aneffective amount of a compound of formula I

[0011] wherein

[0012] X is a bond, CH₂, or CH₂CH₂;

[0013] R and R¹, independently, are hydrogen, hydroxyl, C₁-C₆-alkoxy,C₁-C₆-acyloxy, C₁-C₆-alkoxy-C₂-C₆-acyloxy, R³-substituted aryloxy,R³-substituted aroyloxy, R⁴-substituted carbonyloxy, chloro, or bromo;

[0014] R² is a heterocyclic ring selected from the group consisting ofpyrrolidino, piperidino, or hexamethyleneimino;

[0015] R³ is C₁-C₃-alkyl, C₁-C₃-alkoxy, hydrogen, or halo; and

[0016] R⁴ is C₁-C₆-alkoxy or aryloxy; or

[0017] a pharmaceutically acceptable salt thereof.

[0018] The invention also provides pharmaceutical formulations forinhibiting bone loss comprising a compound of formula I, wherein R, R1,R2, and X are as defined above in an amount that Increases or retainsbone density, together with a pharmaceutically acceptable carrier.

DETAILED DESCRIPTION OF THE INVENTION

[0019] The current invention concerns the discovery that a group of2-phenyl-3-aroylbenzothiophenes (benzothiophenes) of formula I areuseful in the treatment of osteoporosis. The benzothiophenes of formulaI inhibit the loss of bone that results from a lack of endogenousestrogen such as occurs in women following cessation of menstruation dueto natural, surgical, or other processes. The reduction of bone densityand mass that more rarely occurs in men is also tied to the loss ofhormonal regulation and is therefore also a target for therapy accordingto the methods of the current invention.

[0020] The benzothiophenes of formula I are a series of nonsteroidalcompounds that exhibit high affinity for conventional estrogen receptorsin primary sex target tissues. However, they elicit minimal estrogenicresponses in those tissues, and actually serve as potent antagonists ofnatural estrogens such as estradiol. In contrast to the report ofFeldmann, S. et al., “Antiestrogen and antiandrogen administrationreduce bone mass in the rat”, Bone and Mineral, 7:245 (1989), thebenzothiophenes of formula I are able to antagonize classical estrogenicresponses in primary sex target tissues without significantly reducingbone density when given to intact or estrogen treated animals, and theyprevent bone loss in estrogen deficient animals. This dichotomyindicates selective agonist/antagonist actions on specific target cellswhich would appear to be highly desirable in treatment of the menopausalsyndrome. Accordingly, the real benefit of the current discovery is thatthe benzothiophenes of formula I inhibit the loss of bone but do notelicit significant estrogenic responses in the primary sex targettissues. Thus, the current invention provides a method of inhibitingbone loss comprising administering to a human in need of treatment anamount of a compound of formula I that inhibits bone loss but does notsignificantly affect the primary sex target tissues. This combination offeatures allows for long-term treatment of the chronic ailment with adiminished risk of developing the undesirable effects of customaryestrogen replacement therapy.

[0021] The biological action of the benzothiophenes of formula I iscomplex and may be unrelated to the detectable presence of the parentcompound in the blood. Following oral administration of a preferredbenzothiophene of this invention, raloxifene (raloxifene hydrochloride),to human subjects in the clinic, the parent compound was not detected inthe serum of those subjects. It was determined that following oraladministration, the compound was extensively conjugated to theglucuronidated form and cleared quickly from the bloodstream. Althoughno biological endpoints were measured in the human recipients, there wasconcern that the compound was not bioavailable.

[0022] Experiments were undertaken to address the bioavailability issuein laboratory animals where biological activity could be assessed. Theanimal studies indicated that raloxifene was maximally active ininhibiting both uterine uptake of tritiated-estradiol and the normaluterotrophic response to estradiol even under conditions whereraloxifene was extensively conjugated in the plasma of the animals.Moreover, the conjugate, isolated from the urine of human subjectstreated with raloxifene, displayed significantantiestrogenic/antiuterotrophic activity when administered intravenouslyto rats, and inhibited the interaction of tritiated-estradiol with ratuterine estrogen receptors in a manner similar to the parent compound.These studies suggested the conjugated compound may have been convertedto the parental form at the site of action, presumably by the action ofβ-glucuronidase. Such conversion may contribute to the activity of thecompound. β-Glucuronidase is fairly ubiquitous and is thought to beactive in the resorption process of bone remodeling, and wouldpresumably be available for converting the conjugated compound to theparental form if required for activity. Therefore, conjugation of thebenzothiophenes of formula I is not considered to be necessarilydetrimental to their bioavailability as an inhibitor of bone loss.

[0023] Thus, the method of treatment provided by this invention ispracticed by administering to a human in need of inhibition of boneloss, a dose of a compound of formula I or a pharmaceutically acceptablesalt thereof, that is effective to inhibit bone loss. A particularbenefit of this method is that it avoids potentially harmful andunacceptable estrogenic side effects. The inhibition of bone losscontemplated by the present method includes both medical therapeuticand/or prophylactic treatment, as appropriate.

[0024] The method also includes the administration of a compound offormula I given in combination with estrogen. The term estrogen as usedherein refers to any compound which approximates the spectrum ofactivities of the naturally acting molecule which is commonly believedto be 17β-estradiol. Examples of such compounds include estriol,estrone, ethynyl estradiol, Premarin (a commercial preparation ofconjugated estrogens isolated from natural sources—Ayerst), and thelike. Again, due to the selective agonist/antagonist properties of thecompounds of formula I, this combination provides for the full benefitsof estrogen therapy without the concomitant adverse effects associatedwith estrogen therapy alone.

[0025] The general chemical terms used in the description of a compoundof formula I have their usual meanings. For example, the term“C₁-C₃-alkyl” includes such groups as methyl, ethyl, propyl, andisopropyl.

[0026] The term “C₁-C₆-alkoxy” includes such groups as methoxy, ethoxy,propoxy, butoxy, pentyloxy, and hexyloxy and also includes branchedchain structures such as, for example, isopropoxy and isobutoxy.

[0027] The term “C₁-C₆-acyloxy” includes methanoyloxy, ethanoyloxy,propanoyloxy, butanoyloxy, pentanoyloxy, hexanoyloxy, and the like andalso includes branched chain structures such as, for example,2,2-dimethylpropanoyloxy, and 3,3-dimethylbutanoyloxy.

[0028] The term “C₁-C₆-alkoxy-C₂-C₆-acyloxy” contemplates, for example,methoxyethanoyloxy, methoxypropanoyloxy, methoxybutanoyloxy,methoxy-pentanoyloxy, methoxyhexanoyloxy, ethoxyethanoyloxy,ethoxypropanoyloxy, ethoxybutanoyloxy, ethoxypentanoyloxy,ethoxyhexanoyloxy, propoxyethanoyloxy, propoxypropanoyloxy,propoxybutanoyloxy, and the like.

[0029] It should also be understood that as used herein, references toalkyl and alkoxy structures also include cycloalkyl and cycloalkoxygroups where the number of carbons within the structure is at least 3.

[0030] The terms “R³-substituted aryloxy” and “R³-substituted aroyloxy”include such groups as phenyloxy, thienyloxy, furyloxy, naphthyloxy,benzoyloxy, thienoyloxy, furoyloxy, naphthoyloxy, and the like, wherethe R³ substitution group may be hydrogen, hydroxyl, C₁-C₃-alkyl,C₁-C₃-alkoxy, or halo.

[0031] The term “R⁴-substituted carbonyloxy, where the R⁴ substitutiongroup may be C₁-C₆-alkoxy or aryloxy, includes carbonate structures suchas methoxycarbonyloxy ethoxycarbonyloxy, propoxycarbonyloxy,butoxycarbonyloxy, pentyloxycarbonyloxy, hexyloxycarbonyloxy,phenyloxy-carbonyloxy, thienyloxycarbonyloxy, furyloxycarbonyloxy, andnaphthyloxycarbonyloxy.

[0032] Preferred methods of this invention comprise the use of compoundsof formula I wherein R and R¹ are other than hydrogen, alkoxy, aryloxy,chloro, or bromo and therefore represent ester and carbonateconfigurations. Other preferred methods include the use of formula Icompounds wherein R and R¹ are the same as one another. Certain R²groups also demonstrate preferable characteristics when used in themethods of this invention. For example, preferred methods of thisinvention include the use of formula I compounds wherein R² ispiperidino or pyrrolidino, especially piperidino. A further preferredsubgroup of the preferred piperidino and pyrrolidino compounds includecompounds wherein R and R¹ are other than hydrogen and, in particular,those wherein R and R¹ are hydroxyl.

[0033] All of the compounds used in the methods of the current inventioncan be made according to established procedures, such as those detailedin U.S. Pat. No. 4,133,814 and U.S. Pat. No. 4,418,068. In general, theprocess starts with a benzo[b] thiophene having a 6-hydroxyl group and a2-(4-hydroxyphenyl) group. The starting compound is protected,alkylated, and deprotected to form the formula I compounds wherein R andR¹ are both hydroxy. The formula I compounds that are ethers, esters,and carbonates may then be formed if desired. Examples of thepreparation of such compounds are provided in the U.S. patents discussedabove. Specific preparations of yet other derivatized compounds usefulin the current invention are outlined in the Preparations sectionsbelow. Modifications to the above methods may be necessary toaccommodate reactive functionalities of particular substituents. Suchmodifications would be both apparent to, and readily ascertained by,those skilled in the art.

[0034] The compounds used in the methods of this invention formpharmaceutically acceptable acid and base addition salts with a widevariety of organic and inorganic acids and bases and include thephysiologically acceptable salts which are often used in pharmaceuticalchemistry. Such salts are also part of this invention. Typical inorganicacids used to form such salts include hydrochloric, hydrobromic,hydroiodic, nitric, sulfuric, phosphoric, hypophosphoric and the like.Salts derived from organic acids, such as aliphatic mono anddicarboxylic acids, phenyl substituted alkanoic acids, hydroxyalkanoicand hydroxyalkandioic acids, aromatic acids, aliphatic and aromaticsulfonic acids, may also be used. Such pharmaceutically acceptable saltsthus include acetate, phenylacetate, trifluoroacetate, acrylate,ascorbate, benzoate, chlorobenzoate, dinitrobenzoate, hydroxybenzoate,methoxybenzoate, methylbenzoate, o-acetoxybenzoate,naphthalene-2-benzoate, bromide, isobutyrate, phenylbutyrate,β-hydroxybutyrate, butyne-1,4-dioate, hexyne-1,4-dioate, caprate,caprylate, chloride, cinnamate, citrate, formate, fumarate, glycollate,heptanoate, hippurate, lactate, malate, maleate, hydroxymaleate,malonate, mandelate, mesylate, nicotinate, isonicotinate, nitrate,oxalate, phthalate, teraphthalate, phosphate, monohydrogenphosphate,dihydrogenphosphate, metaphosphate, pyrophosphate, propiolate,propionate, phenylpropionate, salicylate, sebacate, succinate, suberate,sulfate, bisulfate, pyrosulfate, sulfite, bisulfite, sulfonate,benzene-sulfonate, p-bromophenylsulfonate, chlorobenzenesulfonate,ethanesulfonate, 2-hydroxyethanesulfonate, methane-sulfonate,naphthalene-1-sulfonate, naphthalene-2-sulfonate, p-toluenesulfonate,xylenesulfonate, tartarate, and the like.

[0035] In addition, some of the formula I compounds may form solvateswith water or organic solvents such as ethanol. These solvates are alsocontemplated for use in the methods of this invention.

[0036] The pharmaceutically acceptable acid addition salts are typicallyformed by reacting a compound of formula I with an equimolar or excessamount of acid. The reactants are generally combined in a mutual solventsuch as diethyl ether or benzene. The salt normally precipitates out ofsolution within about one hour to 10 days and can be isolated byfiltration or the solvent can be stripped off by conventional means.

[0037] Bases commonly used for formation of salts include ammoniumhydroxide and alkali and alkaline earth metal hydroxides, carbonates andbicarbonates, as well as aliphatic and aromatic amines, aliphaticdiamines and hydroxy alkylamines. Bases especially useful in thepreparation of addition salts include ammonium hydroxide, potassiumcarbonate, sodium bicarbonate, calcium hydroxide, methylamine,diethylamine, ethylene diamine, cyclohexylamine and ethanolamine.

[0038] The pharmaceutically acceptable salts generally have enhancedsolubility characteristics compared to the compound from which they arederived, and thus are often more amenable to formulation as liquids oremulsions.

[0039] The current invention also provides useful pharmaceuticalformulations for inhibiting bone loss comprising a formula I compoundplus one or more pharmaceutically acceptable excipients. Pharmaceuticalformulations can be prepared by procedures known in the art. Forexample, the compounds can be formulated with common excipients,diluents, or carriers, and formed into tablets, capsules, suspensions,powders, and the like. Examples of excipients, diluents, and carriersthat are suitable for such formulations include the following: fillersand extenders such as starch, sugars, mannitol, and silicic derivatives;binding agents such as carboxymethyl cellulose and other cellulosederivatives, alginates, gelatin, and polyvinyl pyrrolidone; moisturizingagents such as glycerol; disintegrating agents such as agaragar, calciumcarbonate, and sodium bicarbonate; agents for retarding dissolution suchas paraffin; resorption accelerators such as quaternary ammoniumcompounds; surface active agents such as cetyl alcohol, glycerolmonostearate; adsorptive carriers such as kaolin and bentonite; andlubricants such as talc, calcium and magnesium stearate, and solidpolyethyl glycols.

[0040] The compounds can also be formulated as elixirs or solutions forconvenient oral administration or as solutions appropriate forparenteral administration, for instance by intramuscular, subcutaneousor intravenous routes. Additionally, the compounds are well suited toformulation as sustained release dosage forms and the like. Theformulations can be so constituted that they release the activeingredient only or preferably in a particular part of the intestinaltract, possibly over a period of time. The coatings, envelopes, andprotective matrices may be made, for example, from polymeric substancesor waxes.

[0041] The particular dosage of a compound of formula I required totreat or inhibit bone loss according to this invention will depend uponthe severity of the disease, its route of administration, and relatedfactors that will be decided by the attending physician. Generally,accepted and effective doses will be from about 0.1 to about 1000 mg,and more typically from about 200 to about 600 mg. Such dosages will beadministered to a subject in need of treatment from once to about threetimes each day, or more often as needed to effectively inhibit the boneloss process.

[0042] It is usually preferred to administer a compound of formula I inthe form of an acid addition salt, as is customary in the administrationof pharmaceuticals bearing a basic group such as the piperidino ring. Itis also advantageous to administer such a compound by the oral route toan aging human (e.g. a post-menopausal female or a male showing evidenceof bone loss by X-ray analysis). For such purposes the following oraldosage forms are available.

Formulations

[0043] In the formulations which follow, “Active ingredient” means acompound of formula I. Formulation 1: Gelatin Capsules Hard gelatincapsules are prepared using the following: Ingredient Quantity(mg/capsule) Active ingredient 0.1-1000  Starch, NF 0-650 Starchflowable powder 0-650 Silicone fluid 350 centistokes 0-15 

[0044] The ingredients are blended, passed through a No. 45 mesh U.S.sieve, and filled into hard gelatin capsules.

[0045] Examples of specific capsule formulations containing raloxifenethat have been made include those shown below: Formulation 2: Raloxifenecapsule Ingredient Quantity (mg/capsule) Raloxifene 1 Starch, NF 112Starch flowable powder 225.3 Silicone fluid 350 centistokes 1.7

[0046] Formulation 3: Raloxifene capsule Ingredient Quantity(mg/capsule) Raloxifene 5 Starch, NF 108 Starch flowable powder 225.3Silicone fluid 350 centistokes 1.7

[0047] Formulation 4: Raloxifene capsule Ingredient Quantity(mg/capsule) Raloxifene 10 Starch, NF 103 Starch flowable powder 225.3Silicone fluid 350 centistokes 1.7

[0048] Formulation 5: Raloxifene capsule Ingredient Quantity(mg/capsule) Raloxifene 50 Starch, NF 150 Starch flowable powder 397Silicone fluid 350 centistokes 3.0

[0049] The specific formulations above may be changed in compliance withthe reasonable variations provided.

[0050] A tablet formulation is prepared using the ingredients below:Formulation 6: Tablets Ingredient Quantity (mg/tablet) Active ingredient0.1-1000  Cellulose, microcrystalline 0-650 Silicon dioxide, fumed 0-650Stearate acid 0-15 

[0051] The components are blended and compressed to form tablets.

[0052] Alternatively, tablets each containing 0.1-1000 mg of activeingredient are made up as follows: Formulation 7: Tablets IngredientQuantity (mg/tablet) Active ingredient 0.1-1000 Starch 45 Cellulose,microcrystalline Polyvinylpyrrolidone 4 (as 10% solution in water)Sodium carboxymethyl cellulose 4.5 Magnesium stearate 0.5 Talc 1

[0053] The active ingredient, starch, and cellulose are passed through aNo. 45 mesh U.S. sieve and mixed thoroughly. The solution ofpolyvinylpyrrolidone is mixed with the resultant powders which are thenpassed through a No. 14 mesh U.S. sieve. The granules so produced aredried at 50°-60° C. and passed through a No. 18 mesh U.S. sieve. Thesodium carboxymethyl starch, magnesium stearate, and talc, previouslypassed through a No. 60 U.S. sieve, are then added to the granuleswhich, after mixing, are compressed on a tablet machine to yieldtablets.

[0054] Suspensions each containing 0.1-1000 mg of medicament per 5 mLdose are made as follows: Formulation 8: Suspensions Ingredient Quantity(mg/5 ml) Active ingredient 0.1-1000 mg Sodium carboxymethyl cellulose50 mg Syrup 1.25 mg Benzoic acid solution 0.10 mL Flavor q.v. Color q.v.Purified water to 5 mL

[0055] The medicament is passed through a No. 45 mesh U.S. sieve andmixed with the sodium carboxymethyl cellulose and syrup to form a smoothpaste. The benzoic acid solution, flavor, and color are diluted withsome of the water and added, with stirring. Sufficient water is thenadded to produce the required volume.

[0056] Illustrative compounds that can be used in the formulations andmethods of this invention are shown in Table 1. TABLE 1 Compound No. X Rand R¹ R² Form  1 bond

piperidino base  2 bond

piperidino HCl  3 bond

piperidino base  4 bond

piperidino HCl  5 bond —OC(O)CH₂CH₂CH₃ piperidino base  6 bond—OC(O)CH₂CH₂CH₃ piperidino HCl  7 bond —OC(O)C(CH₃)₃ piperidino base  8bond —OC(O)C(CH₃)₃ piperidino HCl  9 bond —OC(O)CH₂C(CH₃)₃ piperidinobase 10 bond —OC(O)CH₂C(CH₃)₃ piperidino HCl 11 bond

piperidino HCl 12 bond

piperidino base 13 bond —OC(O)OCH₂CH₂CH₂CH₃ piperidino base 14 bond—OC(O)OCH₂CH₂CH₂CH₃ piperidirio HCl 15 bond

piperidino base 16 bond

piperidino HCl 17 bond

piperidino base 18 bond —OC(O)CH₂CH₂OCH₃ piperidino base 19 bond—OC(O)CH₂CH₂OCH₃ piperidino HCl 20 bond OH piperidino base 21 bond OHpiperidino HCl 22 bond H piperidino base 23 CH₂ OH piperidino HCl 24CH₂CH₂ OH piperidino HCl 25 CH₂ H piperidino HCl 26 bond OH pyrrolodinobase 27 bond OH pyrrolodino HCl 28 CH₂ OH pyrrolodino HCl 29 CH₂CH₂ OHpyrrolodino HCl 30 bond H pyrrolodino HCl 31 bond OH hexamethyleneiminoHCl 32 CH₂ OH hexamethyleneimino HCl 33 CH₂CH₂ OH hexamethyleneimino HCl34 bond OCH₃ piperidino HCl

[0057] In the following Preparations, the compound numbers correspond tothose given in Table 1.

Preparation 1

[0058] Preparation of Compound 1:

[0059]6-(4-Fluorobenzoyloxy)-2-[4-(4-fluorobenzoyloxy)phenyl]-benzo[b]thien-3-yl-[4-[2-(piperidin-1-yl)ethoxy]phenyl]-methanone.

[0060] Raloxifene,6-hydroxy-2-(4-hydroxyphenyl)-benzo[b]thien-3-yl-4-[2-(piperidin-1-yl)ethoxyphenyl]-methanonehydrochloride, (5.1 g, 10 mmol) was suspended in 250 mL of drytetrahydrofuran (THF) and 7.1 g (70 mmol) of triethylamine, andapproximately 10 mg of 4-(N,N-dimethylamino) pyridine were added. Thesuspension was cooled in an ice bath and placed under an atmosphere ofnitrogen. 4-Fluorobenzoyl chloride (4.75 g, 30 mmol), dissolved in 20 mLof dry THF, was slowly added over a twenty minute period. The reactionmixture was stirred and allowed to slowly warm to room temperature overa period of eighteen hours. It was then filtered, and the filtrate wasevaporated to a gum in vacuo. The crude product thus obtained wasdissolved in a small volume of chloroform and chromotagraphed (HPLC) ona silica gel column eluted with a linear gradient of solvent, startingwith chloroform and ending with a mixture of chloroform-methanol (19:1(v/v)). The fractions containing the desired product as determined bythin layer chromatography (silica, chloroform-methanol (9:1)) werecombined and evaporated to a gum. The final product was crystallizedfrom ether to give 3.21 g of compound 1.

[0061] PMR: consistent with the structure

[0062] FDMS: m/e=717 M+

[0063] Elemental Analysis for C₄₂H₃₃F₂NO₆S:

[0064] Theor: C, 70.29; H, 4.60; N, 1.95

[0065] Found: C, 70.05; H, 4.60; N, 1.89

[0066] Mol. Wt.: 717

Preparation 2

[0067] Preparation of Compound 2:

[0068]6-(4-Fluorobenzoyloxy)-2-[4-(4-fluorobenzoyloxy)-phenyl]-benzo[b]thien-3-yl-[4-[2-(piperidin-1-yl)ethoxy]-phenyl]-methanonehydrochloride.

[0069] Compound 1 (5.15 g, 7.18 mmol) was dissolved in 25 mL THF, and150 mL ether was added. Dry HCl gas was bubbled into the solution, and awhite gummy precipitate formed. The liquid was removed by decanting, andthe residue was crystallized from ethyl acetate with a small amount ofethanol added to effect solution. The product was filtered, washed withether, and dried to give 4.41 g of Compound 2 as a white powder.

[0070] PMR: consistent with the structure

[0071] Elemental Analysis for C₄₂H₃₄ClF₂NO₆S:

[0072] Theor: C, 66.88; H, 4.54; N, 1.86

[0073] Found: C, 66.59, H, 4.39; N, 1.60

[0074] Mol. Wt.: 753.5

Preparation 3

[0075] Preparation of Compound 3:

[0076]6-(Cyclopropylcarbonyloxy)-2-[4-(cyclopropylcarbonyloxy)-phenyl]benzo[b]thien-3-yl-[4-[2-(piperidin-1-yl)ethoxy]-phenyl]methanone.

[0077] The title compound was prepared using procedures analogous tothose in Preparation 1, but using cyclopropylcarbonyl chloride, exceptthat the product was not crystallized. Yield 2.27 g.

[0078] PMR: consistent with the structure

[0079] FDMS: m/e=610 M+

Preparation 4

[0080] Preparation of Compound 4:

[0081]6-(Cyclopropylcarbonyloxy)-2-[4-(cyclopropylcarbonyloxy)-phenyl]benzo(b]thien-3-yl-[4-[2-(piperidin-1-yl)ethoxy]-phenyl]methanonehydrochloride.

[0082] Compound 4 was prepared from Compound 3 as described inPreparation 2.

Preparation 5

[0083] Preparation of Compound 5:

[0084]6-(n-Butanoyloxy)-2-[4-(n-butanoyloxy)phenyl]benzo[b]thien-3-yl-[4-[2-(piperidin-1-yl)ethoxy]phenyl]methanone.

[0085] Compound 5 was prepared using the method of Preparation 1, butstarting with n-butanoyl chloride, to give 4.12 g of final product as anoil.

[0086] PMR: consistent with the structure

[0087] FDMS: m/e=614 (M⁺¹)

Preparation 6

[0088] Preparation of Compound 6:

[0089]6-(n-Butanoyloxy)-2-[4-(n-butanoyloxy)phenyl]benzo[b]thien-3-yl-[4-[2-(piperidin-1-yl)ethoxy]phenyl]methanonehydrochloride.

[0090] Compound 5 (4.12 g) was dissolved in ethyl acetate (50 mL), and asolution of HCl in ether was added until the precipitation stopped. Theliquid was decanted off, and the white, gummy residue was trituratedwith diethyl ether and filtered. The residue was dried to give 1.33 g ofCompound 6.

[0091] PMR: consistent with the structure

[0092] Elemental Analysis of for C₃₆H₄₀ClNO₆S:

[0093] Theor.: C, 66.50; H, 6.20; N, 2.15

[0094] Found: C, 66.30; H, 6.28; N, 1.98

[0095] Mol. Wt.: 650.24

Preparation 7

[0096] Preparation of Compound 7:

[0097]6-(2,2-Dimethylpropanoyloxy)-2-[4-(2,2-dimethyl-propanoyloxy)phenyl]benzo[b]thien-3-yl-[4-[2-(piperidin-1-yl)ethoxy]phenyl]methanone.

[0098] Compound 7 was prepared using the procedure of Preparation 1, butusing 2,2-dimethylpropanoyl chloride.

Preparation 8

[0099] Preparation of Compound 8:

[0100]6-(2,2-Dimethylpropanoyloxy)-2-[4-(2,2-dimethyl-propanoyloxy)phenyl]benzo[b]thien-3-yl-[4-[2-(piperidin-l-yl)ethoxy]phenyl]methanonehydrochloride.

[0101] Compound 8 was prepared from Compound 7, as described inPreparation 2.

[0102] FDMS: m/e=641 (M-HCl-1)

[0103] Elemental Analysis of C₃₈H₄₄ClN0₆S:

[0104] Theor.: C, 67.29; H, 6.54; N, 2.07

[0105] Found: C, 67.02; H, 6.54; N, 1.90

[0106] Mol. Wt.: 678.29

Preparation 9

[0107] Preparation of Compound 9:

[0108]6-(3,3-Dimethylbutanoyloxy)-2-[4-(3,3-dimethylbutanoyloxy)-phenyl]benzo[b]thien-3-yl[4-[2-(piperidin-1-yl)ethoxy]-phenyl]methanone.

[0109] Compound 9 was prepared using the procedures of Preparation 1,but with 3,3-dimethylbutanoyl chloride.

Preparation 10

[0110] Preparation of Compound 10:

[0111]6-(3,3-Dimethylbutanoyloxy)-2-[4-(3,3-dimethylbutanoyloxy)-phenyl]benzo[b]thien-3-yl[4-[2-(piperidin-1-yl)ethoxy]-phenyl]methanonehydrochloride.

[0112] Compound 10 was prepared from Compound 9 as described inPreparation 2.

[0113] FDMS: m/e=669 (M-HCl-1)

[0114] Elemental Analysis of C₄₀H₄₈ClN0₆S:

[0115] Theor.: C, 68.02; H, 6.85; N, 1.98

[0116] Found: C, 67.75; H, 6.83; N, 2.04

[0117] Mol. Wt.: 706.35

Preparation 11

[0118] Preparation of Compound 11:

[0119]6-(4-Methylbenzoyloxy)-2-[4-(4-methylbenzoyloxy)-phenyl]benzo[b]thien-3-yl[4-[2-(piperidin-1-yl)ethoxy]-phenyl]methanonehydrochloride.

[0120] Compound 11 was prepared from the free base using a proceduresimilar to that of Preparation 2.

[0121] FDMS: m/e=710 (M-HCl-1)

[0122] Elemental Analysis of C₄₄H₄₀ClN0₆S:

[0123] Theor.: C, 70.81; H, 5.39; N, 1.88

[0124] Found: C, 71.10; H, 5.39; N, 1.94

[0125] Mol. Wt.: 746.33

Preparation 12

[0126] Preparation of Compound 12:

[0127]6-Benzoyloxy-2-[4-benzoyloxy)phenyl]benzo[b]thien-3-yl[4-[2-(piperidin-1-yl)ethoxy]-phenyl]methanone.

[0128] Compound 12 was prepared from the appropriate acid chloride asdescribed in Preparation 1.

[0129] FDMS: m/e=682 (M+1)

[0130] Elemental Analysis of C₄₂H₃₅N0₆S:

[0131] Calc: C, 73.80; H, 5.14; N, 2.05

[0132] Found: C, 73.27; H, 5.27; N, 1.94

[0133] Mol. Wt.: 681.8

Preparation 13

[0134] Preparation of Compound 13:

[0135]6-(n-Butoxyoyloxy)-2-[4(n-butoxyoyloxy)phenyl]-benzo[b]thien-3-yl[4-[2-(piperidin-1-yl)ethoxy]-phenyl]methanone.

[0136] Compound 13 was prepared in a manner analogous to that describedin Preparation 1, except that n-butylchloroformate was used in place ofthe acid chloride. Yield=6.13 g in form of oil.

[0137] PMR: consistent with structure

[0138] FDMS: m/e=674 (M+1)

Preparation 14

[0139] Preparation of Compound 14:

[0140]6-(n-Butoxycarbonyloxy)-2-(4(n-butoxycarbonyloxy)phenyl]-benzo[b]thien-3-yl[4-[2-(piperidin-1-yl)ethoxy]phenyl]-methanonehydrochloride.

[0141] Compound 13 was converted to the hydrochloride salt in a manneranalogous to that described in Preparation 6.

[0142] PMR: consistent with structure

[0143] Elemental Analysis of C₃₈H₄₄ClN0₈S:

[0144] Calc: C, 64.26; H, 6.24; N, 1.97

[0145] Found: C, 63.97; H, 6.34; N, 1.98

[0146] Mol. Wt.: 710.29

Preparation 15

[0147] Preparation of Compound 15:

[0148]6-(Phenyloxycarbonyloxy)-2-[4(phenyloxycarbonyloxy)phenyl]-benzo[b]thien-3-yl[4-[2-(piperidin-1-yl)ethoxy]phenyl]-methanone.

[0149] This compound was prepared in a manner analogous to thatdescribed in Preparation 13, but using the appropriate acyl ester.Yield=3.59 g of final product as a tan amorphous powder.

[0150] PMR: consistent with structure

[0151] M: m/e=713 (M+)

Preparation 16

[0152] Preparation of Compound 16:

[0153]6-(Phenyloxycarbonyloxy)-2-[4(phenyloxycarbonyloxy)phenyl]-benzo[b]thien-3-yl[4-[2-(piperidin-1-yl)ethoxy]phenyl]-methanonehydrochloride.

[0154] Compound 15 was converted to the hydrochloride salt in a manneranalogous to that described in Preparation 6.

[0155] PMR: consistent with structure

[0156] Elemental Analysis of C₃₈H₄₄ClN0₈S:

[0157] Calc: C, 67.24; H, 4.84; N, 1.87

[0158] Found: C, 66.94; H, 4.96; N, 1.84

[0159] Mol. Wt.: 750.27

Preparation 17

[0160] Preparation of Compound 17:

[0161]6-(Naphthoyloxy)-2-[4(1-naphthoyloxy)phenyl]benzo[b]thien-3-yl[4-[2-(piperidin-1-yl)ethoxy]phenyl]methanone.

[0162] Compound 17 was prepared as described in Preparation 1 using theappropriate acid halide. Yield=3.5 g of a white amorphous powder.

[0163] PMR: consistent with structure

[0164] FDMS: m/e=781 (M+)

[0165] Elemental Analysis of C₅₀H₃₉N0₆S:

[0166] Calc: C, 76.80; H, 5.03; N, 1.79

[0167] Found: C, 76.53; H, 5.20; N, 1.53

[0168] Mol. Wt.: 781.94

Preparation 18

[0169] Preparation of Compound 18:

[0170]6-(Methoxyethanoyloxy)-2-[4(methoxyethanoyloxy)phenyl]-benzo[b]thien-3-yl[4-[2-(piperidin-1-yl)ethoxy]phenyl]-methanone.

[0171] Compound 18 was prepared as described in Preparation 1 using theappropriate acid halide. Yield=3.61 g of a gummy solid.

[0172] PMR: consistent with structure

[0173] FMDS: m/e=618 (M+1)

Preparation 19

[0174] Preparation of Compound 19:

[0175]6-(Methoxyethanoyloxy)-2-[4(methoxyethanoyloxy)phenyl]-benzo[b]thien-3-yl[4-[2-(piperidin-1-yl)ethoxy]phenyl]-methanonehydrochloride.

[0176] Compound 19 was prepared from 3.5 g of Compound 18 as describedin Preparation 2. Yield =1.65 g of amorphous white powder.

[0177] PMR: consistent with structure

[0178] FDMS: m/e=618 (M+1)

[0179] Elemental Analysis of C₃₄H₃₆N0₈S:

[0180] Calc: C, 62.43; H, 5.55; N, 2.14

[0181] Found: C, 62.23; H, 5.63; N, 2.15

[0182] The following nonlimiting examples illustrate the methods andformulations of this invention.

EXAMPLE 1

[0183] In the examples illustrating the methods, a model ofpost-menopausal osteoporosis was used in which effects of differenttreatments upon femur density were determined.

[0184] Seventy-five day old female Sprague Dawley rats (weight range of225 to 275 g) were obtained from Charles River Laboratories (Portage,Mich.). They were housed in groups of 3 and had ad libitum access tofood (calcium content approximately 1%) and water. Room temperature wasmaintained at 22.2°±1.7° C. with a minimum relative humidity of 40%. Thephotoperiod in the room was 12 hours light and 12 hours dark.

[0185] One week after arrival, the rats underwent bilateral ovariectomyunder anesthesia (44 mg/kg Ketamine and 5 mg/kg Xylazine (Butler,Indianapolis, Ind.) administered intramuscularly). Treatment withvehicle, estrogen, or a compound of formula I was initiated on the dayof surgery following recovery from anesthesia. Oral dosage was by gavagein 0.5 mL of 1% carboxymethylcellulose (CMC). Body weight was determinedat the time of surgery and weekly thereafter and the dosage was adjustedwith changes in body weight. Vehicle or estrogen treated ovariectomized(ovex) rats and non-ovariectomized (intact) rats were evaluated inparallel with each experimental group to serve as negative and positivecontrols.

[0186] The rats were treated daily for 35 days (6 rats per treatmentgroup) and sacrificed by decapitation on the 36th day. The 35 day timeperiod was sufficient to allow maximal reduction in bone density,measured as described herein. At the time of sacrifice, the uteri wereremoved, dissected free of extraneous tissue, and the fluid contentswere expelled before determination of wet weight in order to confirmestrogen deficiency associated with complete ovariectomy. Uterine weightwas routinely reduced about 75% in response to ovariectomy. The uteriwere then placed in 10% neutral buffered formalin to allow forsubsequent histological analysis.

[0187] The right femurs were excised and scanned at the distalmetaphysis 1 mm from the patellar groove with single photonabsorptiometry. Results of the densitometer measurements represent acalculation of bone density as a function of the bone mineral contentand bone width.

[0188] Influence of Raloxifene on Bone Density

[0189] The results of control treatments from five separate experimentsare accumulated in Table 2. In summary, ovariectomy of the rats caused areduction in femur density of about 25% as compared to intact vehicletreated controls. Estrogen, administered in the orally active form ofethynyl estradiol (EE₂), prevented this loss of bone in a dose dependentmanner, but it also exerted a stimulatory action on the uterus resultingin uterine weights approaching that of an intact rat when administeredat 100 μg/kg. Results are reported as the mean of measurements fromthirty rats±the standard error of the mean.

[0190] In these studies, raloxifene also prevented bone loss in a dosedependent manner; however, only minimal increase of uterine weight overthe ovariectomized controls was present in these animals. The results offive assays using raloxifene are combined in Table 3. Accordingly, eachpoint reflects the responses of thirty rats and depicts a typical doseresponse curve for raloxifene in this model. Results are reported as themean±the standard error of the mean. TABLE 2 Bone Density Uterine Weight(mg/cm/cm) (mg) Ovariectomy control 170 ± 3 127 ± 5  (0.5 mL CMC oral)Intact control 220 ± 4 545 ± 19 (0.5 mL CMC oral) EE₂ 100 μg/kg, oral210 ± 4 490 ± 11

[0191] TABLE 3 Bone Density Uterine Weight (mg/cm/cm) (mg) Ovariectomycontrol 171 ± 3 127 ± 5 (0.5 mL CMC oral) Intact control 222 ± 3  540 ±22 (0.5 mL CMC oral) raloxifene 0.01 mg/kg, oral 176 ± 3 150 ± 5raloxifene 0.10 mg/kg, oral 197 ± 3 196 ± 5 raloxifene 1.00 mg/kg, oral201 ± 3 199 ± 5 raloxifene 10.00 mg/kg, oral 199 ± 3 186 ± 4

EXAMPLE 2

[0192] Raloxifene was administered alone or in combination with ethynylestradiol. Rats treated with raloxifene alone had uterine weights whichwere marginally higher than the ovariectomized controls and much lessthan those of ethynyl estradiol treated rats, which approached those ofthe intact controls. Conversely, raloxifene treatment significantlyreduced bone loss in ovariectomized rats, and when given in combinationwith ethynyl estradiol it did not appreciably reduce the protectiveeffect of the estrogen on bone density. The results are shown in Table4. TABLE 4 Bone Density Uterine Weight (mg/cm/cm) (mg) Experiment AOvariectomy control 162 ± 4 142 ± 18 (0.5 ml, CMC oral) Intact control219 ± 5 532 ± 49 (0.5 mL CMC oral) EE₂ 100 μg/kg, oral 202 ± 6 450 ± 17EE, 100 μg/kg + 204 ± 2 315 ± 10 raloxifene 0.10 mg/kg, oral EE₂ 100μg/kg + 200 ± 5 250 ± 21 raloxifene 1 mg/kg, oral Experiment BOvariectomy control 165 ± 8 116 ± 6  (0.5 mL CMC oral) Intact control220 ± 4 605 ± 69 (0.5 mL CMC oral) EE, 100 μg/kg, oral  215 ± 11 481 ±24 raloxifene 1 mg/kg + 197 ± 7 263 ± 17 EE₂ 100 μg/kg, oral raloxifene1 mg/kg  198 ± 11 202 ± 5 

EXAMPLE 3

[0193] The ability of raloxifene to inhibit bone loss was compared tothat of tamoxifen (SIGMA, St. Louis, Mo). Tamoxifen, a well knownantiestrogen currently used in the treatment of certain cancers, hasbeen shown to inhibit bone loss (see for example, Love, R., et al. 1992“Effects of tamoxifen on bone mineral density in postmenopausal womenwith breast cancer”, N Eng J Med 326:852; Turner, R., et al. 1988“Tamoxifen inhibits osteoclast-mediated resorption of trabecular bone inovarian hormone-deficient rats”, Endo 122:1146). A relatively narrowrange of doses of raloxifene and tamoxifen was administered orally toovariectomized rats as in the previous example. Although both of theseagents displayed the ability to prevent reduction of femur density whileevoking only modest uterotrophic activity, as identified by gains inuterine weight (Table 5), a comparison of several histologicalparameters demonstrated a marked difference between the rats treatedwith these agents (Table 6).

[0194] Increases in epithelial height are a sign of estrogenicity oftherapeutic agents and may be associated with increased incidence ofuterine cancer. When raloxifene was administered as described in Example1, only at one dose was there any statistically measurable increase inepithelial height over the ovariectomized controls. This was in contrastto the results seen with tamoxifen and estrogen. At all doses given,tamoxifen increased epithelial height equal to that of an intact rat,about a six-fold increase over the response seen with raloxifene.Estradiol treatment increased epithelial height to a thickness greaterthan intact rats.

[0195] Estrogenicity was also assessed by evaluating the adverseresponse of eosinophil infiltration into the stromal layer of the uterus(Table 6). Raloxifene did not cause any increase in the number ofeosinophils observed in the stromal layer of ovariectomized rats whiletamoxifen caused a significant increase in the response. Estradiol, asexpected, caused a large increase in eosinophil infiltration.

[0196] Little or no difference was detectable between raloxifene andtamoxifen effects on thickness of the stroma and myometrium. Both agentscaused an increase in these measurements that was much less than theeffect of estrogen.

[0197] A total score of estrogenicity, which was a compilation of allfour parameters, showed that raloxifene was significantly lessestrogenic than tamoxifen. TABLE 5 Bone Density Uterine Weight(mg/cm/cm) (mg) Ovariectomy control 171 ± 5  126 ± 17 (0.5 mL CMC oral)Intact control 208 ± 4  490 ± 6  (0.5 mL CMC oral) EE₂ 100 μg/kg, oral212 ± 10 501 ± 37 raloxifene 1 mg/kg, oral 207 ± 13 198 ± 9  tamoxifen 1mg/kg, oral 204 ± 7  216 ± 18

[0198] TABLE 6 Epithelial Stromal Myometrial Stromal Height EosinophilsThickness Expansion Ovariectomy control 1.24 1.00 4.42 10.83 (0.5 mL CMCoral) Intact control (0.5 mL CMC oral) 2.71 4.17 8.67 20.67 EE₂ 100μg/kg, oral 3.42 5.17 8.92 21.17 raloxifene 1 mg/kg 1.67 1.17 5.42 14.00tamoxifen 1 mg/kg 2.58 2.83 5.50 14.17

EXAMPLE 4

[0199] Other compounds of formula I were administered orally in the ratassay described in Example 1. Table 7 reports the effect of a 1 mg/kgdose of each compound in terms of a percent inhibition of bone loss andpercent uterine weight gain. TABLE 7 Compound % Inhibition % UterineNumber of Bone Loss^(a) Weight Gain^(b) 2 86 26 6 24 19 8 66 24 10 52 2411 26 28 12 60 15 14 121 32 16 108 25 18 21 17 27 25 1 34 26 −6

[0200]

EXAMPLE 5

[0201] Fracture rate as a consequence of osteoporosis is inverselycorrelated with bone mineral density. However, changes in bone densityoccur slowly, and are measured meaningfully only over many months oryears. It is possible, however, to demonstrate that the formula Icompounds, such as raloxifene, have positive effects on bone mineraldensity and bone loss by measuring various quickly respondingbiochemical parameters that reflect changes in skeletal metabolism. Tothis end, in a current test study of raloxifene at least onehundred-sixty patients are enrolled and randomized to four treatmentgroups: estrogen, two different doses of raloxifene, and placebo.Patients are treated daily for eight weeks.

[0202] Blood and urine are collected before, during, and at theconclusion of treatment. In addition, an assessment of the uterineepithelium is made at the beginning and at the conclusion of the study.Estrogen administration and placebo serve as the positive and negativecontrols, respectively.

[0203] The patients are healthy post-menopausal (surgical or natural)women, age 45-60 who would normally be considered candidates forestrogen replacement in treatment for osteoporosis. This includes womenwith an intact uterus, who have had a last menstrual period more thansix months, but less than six years in the past.

[0204] Patients who have received any of the following medicationssystematically at the beginning of the study are excluded from thestudy: vitamin D, corticosteroids, hypolipidemics, thiazides, antigoutagents, salicylates, phenothiazines, sulfonates, tetracyclines,neomycin, and antihelmintics. Patients who have received any estrogen,progestin, or androgen treatment more recently than three months priorto the beginning of the study; patients who have ever receivedcalcitonin, fluoride, or bisphosphonate therapy; patients who havediabetes mellitus; patients who have a cancer history anytime within theprevious five years; patients with any undiagnosed or abnormal genitalbleeding; patients with active, or a history of, thromboembolicdisorders; patients who have impaired liver or kidney function; patientswho have abnormal thyroid function; patients who are poor medical orpsychiatric risks; or patients who consume an excess of alcohol or abusedrugs.

[0205] Patients in the estrogen treatment group receive 0.625 mg/day andthe two raloxifene groups receive dosages of 200 and 600 mg/day, allgroups receiving oral capsule formulations. Calcium carbonate, 648 mgtablets, is used as calcium supplement with all patients taking 2tablets each morning during the course of the study.

[0206] The study is a double-blind design. The investigators and thepatients do not know the treatment group to which the patient isassigned.

[0207] A baseline examination of each patient includes quantitativemeasurement of urinary calcium, creatinine, hydroxyproline, andpyridinoline crosslinks. Blood samples are measured for serum levels ofosteocalcin, bone-specific alkaline phosphatase, raloxifene, andraloxifene metabolites. Baseline measurements also include examinationof the uterus including uterine biopsy.

[0208] During subsequent visits to the investigating physician,measurements of the above parameters in response to treatment arerepeated. The biochemical markers listed above that are associated withbone resorption have all been shown to be inhibited by theadministration of estrogen as compared to an untreated individual.Raloxifene is also expected to inhibit the markers in estrogen deficientindividuals as an indication that raloxifene is effective in inhibitingbone loss from the time that treatment is begun.

[0209] Subsequent longer term studies can incorporate the directmeasurement of bone density by the use of a photon absorptiometry andthe measurement of fracture rates associated with therapy.

We claim:
 1. A method of inhibiting bone loss comprising administeringto a human in need of treatment an effective amount of a compound offormula I

wherein X is a bond, CH_(2,) or CH₂CH₂; R and R¹, independently, arehydrogen, hydroxyl, C₁-C₆-alkoxy, C₁-C₆-acyloxy,C₁-C₆-alkoxy-C₂-C₆-acyloxy, R³-substituted aryloxy, R³-substitutedaroyloxy, R⁴-substituted carbonyloxy, chloro, or bromo; R² is aheterocyclic ring selected from the group consisting of pyrrolidino,piperidino, or hexamethyleneimino; R³ is C₁-C₃-alkyl, C₁-C₃-alkoxy,hydrogen, or halo; and R⁴ is C₁-C₆-alkoxy or aryloxy; or apharmaceutically acceptable salt thereof.
 2. A method of claim 1 whereinthe human has been diagnosed as suffering from osteoporosis.
 3. A methodof claim 1 wherein the human is a post-menopausal female.
 4. A method ofclaim 1 wherein the human is a male.
 5. A method of claim 1 wherein thecompound is administered prophylactically.
 6. A method of claim 1wherein X is a bond.
 7. A method of claim 1 wherein R² is piperidino orpyrrolidino.
 8. A method of claim 6 wherein R² is piperidino orpyrrolidino.
 9. A method of claim 6 wherein R² is piperidino.
 10. Amethod of claim 6 wherein R² is pyrrolidino.
 11. A method of claim 1wherein R and R¹ are both hydroxyl, C₁-C₆-acyloxy,C₁-C₆-alkoxy-C₂-C₆-acyloxy, R³-substituted aroyloxy, or R⁴-substitutedcarbonyloxy.
 12. A method of claim 11 wherein R and R¹ are bothhydroxyl.
 13. A method of claim 11 wherein R and R¹ are bothC₁-C₆-acyloxy.
 14. A method of claim 13 wherein R and R¹ are bothn-butanoyloxy, 2,2-dimethylpropanoyloxy, or 3,3-dimethylbutanoyloxy. 15.A method of claim 11 wherein R and R¹ are both R⁴-substitutedcarbonyloxy.
 16. A method of claim 15 wherein R and R¹ are bothmethoxycarbonyloxy or phenyloxycarbonyloxy.
 17. A method of claim 11wherein R and R¹ are both R³-substituted aroyloxy.
 18. A method of claim17 wherein R and R¹ are both benzoyloxy, methylbenzoyloxy, ornaphthoyloxy.
 19. A method of claim 8 wherein R and R¹ are bothhydroxyl, C₁-C₆-acyloxy, C₁-C₆-alkoxy-C₂-C₆-acyloxy, R³-substitutedaroyloxy, or R⁴-substituted carbonyloxy.
 20. A method of claim 9 whereinR and R¹ are both hydroxyl.
 21. A method of claim 10 wherein R and R¹are both hydroxyl.
 22. A method of claim 8 wherein R and R¹ are bothC₁-C₆-acyloxy.
 23. A method of claim 22 wherein R and R¹ are bothn-butanoyloxy, 2,2-dimethylpropanoyloxy, or 3,3-dimethylbutanoyloxy. 24.A method of claim 8 wherein R and R¹ are both R⁴-substitutedcarbonyloxy.
 25. A method of claim 24 wherein R and R¹ are bothmethoxycarbonyloxy or phenyloxycarbonyloxy.
 26. A method of claim 8wherein R and R¹ are both R³-substituted aroyloxy.
 27. A method of claim26 wherein R and R¹ are both benzoyloxy, methylbenzoyloxy, ornaphthoyloxy.
 28. A method of claim 1 wherein the compound of formula Iis administered in an amount of 0.1 to 1000 mg.
 29. A method of claim 1wherein the compound of formula I is administered in an amount of 200 to600 mg.
 30. A method of claim 1 wherein the compound of formula I isadministered in an amount of 600 to 1000 mg.
 31. A method of claim 20wherein the human has been diagnosed as suffering from osteoporosis. 32.A method of claim 20 wherein the human is a post-menopausal woman.
 33. Amethod of claim 20 wherein the compound is administeredprophylactically.
 34. A method of claim 1 wherein the administration ofa compound of formula I does not significantly affect the primary sextarget tissues.
 35. A method of claim 1 wherein a compound of formula Iis administered in combination with estrogen.